Processes for producing 4,6-bis (substituted)phenylazoresorcinols
US5962740A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1998 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Apr 28, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C245/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for producing 4,6-bisphenylazoresorcinol of formula 2! wherein R represents halogen atom, C.sub.1-5 alkyl group, hydroxycarbonyl or C.sub.1-5 alkoxy group, n represents 0 or an integer of 1 to 5, and two or more Rs are the same or different from each other, which comprises reacting resorcinol with a benzenediazonium salt of formula 1! wherein R and n are the same as defined in the above formula 1!, and X represents Cl, Br, OSO.sub.3 H or OPO.sub.3 H.sub.2, in an alkaline solvent, characterized in that (a) a solution of the compound of the formula 1! is mixed with a solution or suspension of an alkali metal or alkaline earth metal hydroxide to obtain an alkaline mixture, and this alkaline mixture is mixed to be reacted with a solution or suspension containing resorcinol and/or its alkali metal salt or alkaline earth metal salt, or (b) a solution of the compound of formula 1! is mixed to be reacted with a solution or suspension of a mixture of resorcinol with its alkali metal hydroxide or alkaline earth metal hydroxide 15 to 40 times by mol as much as the resorcinol. By the above-described method, the reaction volume can be reduced as compared with the conventional processe…
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